Air stratifier



L. G. M LEAN AIR STRATIFIER April 21, 1953 4 Sheets-Sheet 1 Filed June1, 1948 INVEN TOR. G. MC LEAN LYLE ATTOR N EY L. G. M LEAN AIRSTRATIFIER ApriI 21 1953 4 Sheets-Sheet 2 Filed June 1, 1948 INVENTOR.MCLEAN LYLE ATTORNEY April 21, 1953 G. M LEAN 2,535,753

AIR STRATIFIER Filed June 1, 1948 4 Sheeis-Sheet 5 38 'IHI' mm], as 34I2 1.

QIHHi IN VEN TOR. LYLE G MCLEAN 9 BYgzdg' AT TORN EY April 21, 1953 1 G,McLEfiN 2,635,753

AIR STRATIFIER Filed June 1, 1948 Q 4 heets-Sheet 4 AVIL v.ZIZIGIEIEIQIEIEIZltI-QIEIEI 1Q INVENTOR. 3 LYLE c MCLEAN "NJ." w; 9 BYATTO R N EY Patented Apr. 21, 1953 .UNITED STATES PATENT OFFICE AIRSTRATIFIER Lyle G. McLean, Warden, Wash.

Application June 1, 1948, Serial No. 30,439

8 Claims. 1

With my new and improved classifier and separator, I move the materialin a horizontal plane over a perforated level plate, the saidperforations discharging positive air pressure up through the materialwhich is being moved over the said plate by a network or open conveyor.The air pressure being discharged from the openings or nozzles in saidplate is diffused by and through the conveyor and the material, forcingthe lighter materials to the top while concentrates gravitate to thebottom.

The movement of the conveyor eliminates what is known as pin holes orchannels forming in the finer materials, thereby preventing the air fromescaping through to the atmosphere through said pin holes or channels.In the case of the coarse granular materials, the said conveyor alsoprevents the air from forcing aside the said coarse particles formingchannels to the surface of the materials and escaping. The levelmovement of the conveyor through the materials insures a uniform anddirect lift by the air to the materials, causing a complete and uniformstratification of the materials.

After the floatation and stratification of the materials has beencompleted I employ two or more methods of separating the lightermaterials from the coarse materials. One of my methods is to employ amechanical conveyor adjustably mounted relative to the various strata ofmaterials to be separated.

-Another method of separating the lighter material from the heaviermaterial is by a vacuum hood and conveyor, said vacuum being capable ofcontrol above the stratified material. By using both of the abovemethods three or more strata of material can be separated.

In the design of the jets within my machine, the area of the said jetsare less than the total volume of air being delivered to said jets. Thisprovides an even discharge of air over the entire surface of the plateand through the material regardless of the pressures being employed forthe separation or Stratification of the material.

The primary object of my invention is to classify and separategranulated materials by the floatation of the lighter materials to theirrespective strata by air passing up through the said materials, thematerials being moved relative to one another soas to diffuse the airpassing therethrough, causing the lighter materials to rise to thesurface and the heavier materials to concentrate underneath said lightermaterials.

Another object of my invention is the designing of a concentrator andclassifying machine wherein a continuous flow of material will passthrough said machine, said material being stratified and separated bydiffused air passing up through the material.

Another object of my invention is the provision of a vacuum lift orconveyor for removing the upper lighter strata of material away from thecoarser and heavier materials.

Another object of the invention is the coordination of relative pressureand vacuum ratios between a positive diffused air delivered evenly upthrough the material, and a vacuum created above the material effectingthe separation between. the lighter and heavier materials.

Another object of the invention is to increase or decrease diffused airpressures passing up through the materials as they progress through themachine.

Another object of the invention is to control the diffused air pressurespassing up through the materials in relation to the amount of vacuumbeing applied above the materials, effecting the desired strataseparation between the lighter materials and the heavier.

Another object of the invention is to remove intermediate strata ofmaterial by a direct adjustable mechanical means.

Another object of the invention is the combination of the vacuum strataremoval and two or more mechanical means for removing the various strataof material.

Summing up the above statements and objects, it must be borne in mindthat as the materials are moved over the jets of air they become fluidin action, due to the even diffused distribution of air lifting thematerial to its various strata depending on the weight of the materialsin said strata, in other words the entire material is floating in afluid body over the said diffused air throughout its progress throughthe machine, thereby it becomes very easy to separate the strata onefrom the other by both vacuum and mechanical means.

Referring to the drawings:

Figure 1 is a side sectional view of my new and 3 improved classifierand separator, parts broken away for convenience of illustration.

Figure 2 is a fragmentary enlarged detail of the air discharge holes,together with the special conveyor agitating screen.

Figure 3 is a sectional view, taken on line 3-3 of Figure 2.

Figure 4 is a perspective view of the separator, parts broken away forconvenience of illustration, the frame of the machine being completelyremoved therefrom.

Figure 5 is an end sectional view taken on line 5-5 of Figure 1. Thisview includes the driving motor. 7

Figure 6 is a plan view of my new and improved classifier and separator.

Figure 7 is a detail fragmentary plan view of materials from theconcentrates.

Figure 8 is a cross sectional view taken yer-V tically andlongitudinally of the conveyor-shown in Figure '7.

Figure 9 is a fragmentary view in elevation taken on line 9-9 of Figure'7, illustrating the mechanical structure.

Ref rrin mor P C fiUBJIY t0 the d awin s:

My new and improved classifier and separator consists of an endlessnetwork conveyor l, trained about the rollers 2, ,3, 4, 5 and 6. Theserollers are journalled to the frame I of the machine by bearings 8 and9. The roller 6 is driven by the motor In through the reduction gear H,belt 52, through the cross shaft it, journalled within the bearings 9.

A sub-frame-M is supported upon themain frame 1 by the legs l5, bestillustrated in Figure 5. Horizontally mounted upon the sub-frame i l isa level perforated plate [6, having perforations I! therethroughpermitting air to pass through said plate from the air nozzles l8, l9and 26, which will be more fully described later.

Mounted upon the frame i i and above the plate is is a trough 2|, alongwhich is conveyed the materials to be classified and separated. Thistrough consists of side walls 22 having a hopper 23 for distributing thematerials on to the conveyor belt 1 on its one end, and having a vacuumnozzle 24 mounted upon its opposite or delivery end (Figs. 1, 4 and 5).The trough is closed at its receiving end by the end plate 25 and the vflexible closure door 26, which allows the conveyor belt I to passthereunder, best illustrated in Figures 1 and 4.

I have provided an adjustable vacuum maintaining plate 21 at theentrance to the vacuum nozzle 24, the object of this plate is tomaintain a vacuum closure between the surface 23 of the materials andthe nozzle 24, the vacuum removing the lighter materials 29 from theheavier materials as the said materials are conveyed through themachine. A second adjustable plate 3B is provided adajcent the dischargeend of the conveyor I, which maintains a vacuum seal above theconcentrates 3! adjacent the vacuum nozzle 24, allowing the separationbetween the finer materials 29 and the concentrates ti.

The objects of the plates 27 and St is primarily intended to maintainthe vacuum seal between the surface of the finer materials 29 beforeentering the nozzle 24 from above the concentrates 31.

A control valve 32 is provided in the vacuum pipe 33 for controlling theamount of vacuum existing at the intake end of the nozzle 2 differentmaterials requiring various amounts of vacuum. An air supply line 34delivers air to the control valves 35, which delivers air into the airnozzles I8, is and 20. Located in the bottom of the said nozzles arepillars or spindles 36. As the air enters the side of the nozzlesthrough the openings 37 and strike the said pillar a whirling action isimparted to the air distributing the air more evenly over the undersideof the perforated plate l6, breaking up the air currents.

Referring to Figure 5, I have provided a clean out plug 38 for removingthe materials which ordinarily get in the nozzle through the openings llof the perforated plate It.

I will now describe the operation of my new and improved classifing andseparating machine. The materials are entered through the hopper 23 onto the network conveyor 2, which is travelling in the direction of thearrow, driven by the motor 593. Air is supplied from the supply line 34through the valves into the nozzles l8, l9 and 28 up through the holesI! of the plate it, through the conveyor i, up through the materials,floating the lighter materials to the top as indicated best at 28 andconcentrating the heavier materials 3: on the conveyor (best illustratedin Figure 1), under the vacuum nozzle 23 and the delivery end of theconveyor at 39.

As the materials travel under the. vacuum nozzle 24, the lightermaterials are removed from the surface of the concentrates 3! by Vacuum.The amount of vacuum will depend upon the type of material beingseparated and this is controlled by the by-pass valve 32. The valves 35delivering air into the nozzles l8, I9 and 20 may be adjusted at variousopenings delivering the required pressures through the said nozzles andthrough the perforated plate It and the materials. This gives a controlon the amount of air pressure applied for the floatation of the lightermaterials which may be varied during the progress of the movement of theconveyor belt 3 and the material through the trough 2 I. For instancethe pressure developed within the nozzles l8, l9 and 20 may differeither increasing or decreasing the velocity of the air being dischargedthrough the openings or nozzles 11 of the plate It, as the materials areconveyed through the machines. An adjustment between the ratio of vacuumand pressure through the plate it) may be made by adjusting the valve 32inthe vacuum line and the valves 35 in the pressure supply line 34leading to the nozzle 25.

The pressure nozzle 28 is carefully adjusted relative to the vacuumexisting in the nozzle '24, said adjustments providing for differentrequirements for the separation of the finer materials from theconcentrates 3! under the nozzle 24. As the conveyor belt I travels overthe perforated plate it moves the materials in such a manner as tomaintain an even flow of diffused air pressure up through the materialscreating a fluid condition of the said materials permitting the carryingout of an even classification of the lighter materials from theconcentrates, preventing pin holes in the material and channeling of theair.

It is to be particularly noted that the conveyor moving in a horizontalplane guides the stratified material forward relative to the dischargeend of the conveyor and, as the material is moved forwardly, it isevenly stratified. The material being level, it functions to diffuse theair and the material is thereby more efficiently stratified. The blanketor bed of material aids in the diffusion of the air, and an even airpressure is obtained, with the air giving a direct lift to the aeezsgwseparticles and the material beln'g'moved in relation to thestratificationthereof.

Referring to Figures 7, Band 9, I have illustrated anotherpreferred'method of separating the lighter materials from theconcentrates con- 'sisting of a screw conveyor 40 mounted withinbearings 4| supported by the scoop or separator.

.The scoop or lip, i2 is supportedby the brackets .43, and is.adjustablefor. elevation by the hand wheels M :whichholds saldglip atthe desired elevation. This, comprises the, Separating feature of thescoop and is adjustable up and down relative to the fiher materials 29and the concentrates 3!, best illustratedin Figure 8. This'sys 1 1 1 sea atin h difififififij of. terial is admirably adapted to various typesof materials.

It will be noted in Figure 7 that the conveyor screw will delivermaterials from the center of the machine outwardly in both directions,which is a feature of the conveyor itself. The walls 46 form part of thetrough t2 and is for the purpose of guiding the concentrates 3| alongtheir predetermined path through the trough 2! to the final dischargepoint 39. I have provided suitable driving means, as the motor 41 fordriving the conveyor 40 through the belt 48.

Referring to Figure 8, I have illustrated in broken line position thevacuum head 2% being used in combination with the screw conveyor forseparating the various strata of materials. The vacuum head takes awaythe lightest material, while the screw conveyor removes the intermediatestrata, and lastly the conveyor l delivers the heavy concentrates 3ifrom the machine.

Reviewing the operation, and restating the primary object of myinvention, is the creation of a fluid condition to a moving stream ofmaterials so that the said materials may be stratified and separated.This is accomplished by floating the material on diffused air bymechanical action, namely moving about of the material over air nozzles,eliminating the by-passing of the air up through the material into theatmosphere without first being completely diffused under the materialgiving a complete air lifting action to the material. This is thefeature that is new in my system of operation, and that heretofore hasnot been accomplished to my knowledge in other machines, even thoughthey used air up through the material.

When the materials have become fluid, the ideal condition exists forremoving the various strata of material, first by a vacuum for thelighter materials, then by the mechanical means, which I have discussedconsisting of the screw conveyor and the network conveyor, although I donot wish to be limited to the exact mechanical means illustrated, asother methods may be employed still coming within the scope of myclaims.

What I claim is: a

l. A combined classifier and material separator, comprising a frame, aperforated plate horizontally supported on the frame, a foraminousconveyor movable horizontally over the surface of the perforated plate,a hopper on said frame for depositing a layer of material on saidconveyor, a suction chamber on said frame and spaced from said hopperlongitudinally of said conveyor and disposed completely across andperpendicular to said conveyor for removing the upper portion of saidmaterial layer, means on said frame for confining the layer of materialto be treated on the conveyor between the hopper and the suctionchamber, and means supported by said frame .for supplying air underpressure substantially perpendicular to and through the perforations ofsaid plate and through the material to agitate and stratify the variouselements of the material whilein movement between the hopper and thesuction chamber.

2. The combination of claim 1, wherein said suction chamber movablysupports on its respective transverse walls a pair of vertical plates:disposed transversely abovethe conveyor, and

means for securing said plates on said chamber walls in selectivepositions of elevation relative to said conveyor.

.3. A combined classifier and material separator comprising a frame, aperforated plate horizontally supported on the frame, a foraminousconveyor operatively mounted on the frame and having a horizontalflight, said flight being superposed on the plate and movablelongitudinally thereof and having a loading end and opposite dischargeend, a hopper for depositing material on the loading end of the flight,means spaced from the loading end of the flight and disposed adjacent tothe discharge end of the flight for removing the upper strata of thematerial layer with the lower heavier strata of the layer being dumpedoff the discharge end of the flight, means for confining the material onthe conveyor between the loading and discharge ends thereof, a pluralityof longitudinally spaced air suppliers mounted beneath and perpendicularto the plate for supplying air under pressure vertically through theplate and through the layer of material to agitate and uniformlystratify the various elements of the material while it is moved by theconveyor from the hopper to the discharge end of the flight, and controlmeans for each of said air suppliers for individually regulating the airsupplied thereby.

4. The combination of claim 3, wherein said means for removing the upperstrata comprises a suction chamber mounted on said frame for verticaladjustment relative to said conveyor, one of said air suppliers beingvertically aligned with the chamber for cooperation with said suctionmeans in removing the upper strata.

5. A dry floatation classifier and separator, comprising a frame, aperforated plate horizontally supported on the frame, a foraminous con-'veyor movable horizontally over the surface of the perforated plate andhaving a loading end and a discharge end, a hopper for depositingmaterial on said conveyor adjacent the loading end thereof, means onsaid frame for confining the material to be treated on the conveyorbetween the hopper and the discharge end of said conveyor, meanssupported by said frame beneath said plate for supplying air underpressure substantially perpendicular to and up through the perforationsof said plate and through said conveyor and the material to agitate andstratify the various elements of the material while in movement betweenthe hopper and the discharge end, and means above said plate andconveyor adjacent the discharge end thereof and disposed completelythereacross between said confining means for removing the upper portionof the stratified material.

6. The combination of claim 5, wherein said material removing meansincludes a scoop disposed transversely above the discharge end of theconveyor flight and having a lead edge facing the hopper and opposed tothe longitudinal aeespse path of the movement of the conveyor flight forscooping off the upper portion of the material as the material is movedby the conveyor, and a screw conveyor rotatably journalled in the scopeand having reverseiy spiralled ends to discharge the scooped materialfrom both sides of the frame.

7. The combination of claim 6, wherein said scoop is mounted on theframe for vertical adjustment relative to the conveyor flight and meansis provided for adjusting said scoop.

8. A dry floatation classifier and separator, as defined in claim 5,wherein said means for removing the upper portion of the materialcomprises vacuum means.

LYLE- G. McLEAN.

References Cited in the die of this patent UNITED STATES PATENTS NumberNumber 7 455,219

Name Date Davis -1 Sept. 21, 1897 Gillon et a1 Sept. 11, 1906 Reed1.11.... Jan. 14, 1919 Fraser 1 Mar. 10, 1942 Brusset s i Feb. 9, 1943stump Us 1- Oct. 19, 1943 Wiegand -1 Aug. 14, 1945 FOREIGN PATENTBCountry Date Great Britain a Oct. 12. 1936

